Search results
Results From The WOW.Com Content Network
Chromosome abnormality. A chromosomal abnormality, chromosomal anomaly, chromosomal aberration, chromosomal mutation, or chromosomal disorder is a missing, extra, or irregular portion of chromosomal DNA. [1][2] These can occur in the form of numerical abnormalities, where there is an atypical number of chromosomes, or as structural ...
A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosome abnormality. Although polygenic disorders are the most common, the term is mostly used when discussing disorders with a single genetic cause ...
Down syndrome is the most common chromosomal abnormality in humans. [9] Globally, as of 2010, Down syndrome occurs in about 1 per 1,000 births [1] and results in about 17,000 deaths. [142] More children are born with Down syndrome in countries where abortion is not allowed and in countries where pregnancy more commonly occurs at a later age. [1]
The following is a list of genetic disorders and if known, type of mutation and for the chromosome involved. Although the parlance "disease-causing gene" is common, it is the occurrence of an abnormality in the parents that causes the impairment to develop within the child. There are over 6,000 known genetic disorders in humans.
Turner syndrome (TS), also known as 45,X, or 45,X0, is a genetic disorder in which cells have only one X chromosome or are partially missing an X chromosome (sex chromosome monosomy) leading to the complete or partial deletion of the pseudoautosomal regions (PAR1, PAR2) in the affected X chromosome. [2][6][7] Most people have two sex ...
Prader–Willi (PWS) and Angelman syndrome (AS) are distinct neurogenetic disorders caused by chromosomal deletions, uniparental disomy or loss of the imprinted gene expression in the 15q11-q13 region. Whether an individual exhibits PWS or AS depends on if there is a lack of the paternally expressed gene to contribute to the region.
Chromosomal instability can in turn cause cancer. However, chromosomal instability syndromes such as Bloom syndrome, ataxia telangiectasia and Fanconi anaemia are inherited [14] and are considered to be genetic diseases. These disorders are associated with tumor genesis, but often have a phenotype on the individuals as well.
DiGeorge syndrome, also known as 22q11.2 deletion syndrome, is a syndrome caused by a microdeletion on the long arm of chromosome 22. [7] While the symptoms can vary, they often include congenital heart problems, specific facial features, frequent infections, developmental disability, intellectual disability and cleft palate. [7]